In cross lappers having an upper carriage and a lower carriage, called laying carriage, through which endless card web transport belts are passed to transport a card web to be cross-layered onto an output conveyor belt to form a fleece, the course of the card web transport belts is rather complicated.
From EP 0 865 521 B1, a cross lapper is known, comprising a laying carriage movable on rails in a machine stand transversely with respect to an output conveyor belt above same, and an upper carriage as well as a plurality of card web transport and laying belts for transporting the card web via the upper carriage and the laying carriage into a discharge nip formed at the laying carriage for depositing the card web on an output conveyor belt. A card web receiving section comprises a belt entrance of the transport and laying belts (hereinafter referred to as the card web transport belts), having a downwardly inclined entrance zone with two adjacently extending belt sections of the card web transport belts. The belt sections joined at the entry of the belt entrance form a narrow entrance nip which is adapted to the card web thickness, and they extend in the entrance path substantially in parallel or at an acute angle with respect to one another and so close to one another that they guide or cover the card web in the entrance path on both sides. In this cross lapper, the two card web transport belts are passed through the upper carriage and the laying carriage.
U.S. Pat. No. 6,195,844 B1, EP 0 517 563 B2, U.S. Pat. No. 3,877,628, EP 0 517 568 B1, WO 2004/013390 A1, EP 0 659 220 B1 and EP 1 010 786 B1 show cross lappers in which both belts transporting the card web into the discharge nip at the laying carriage and onto the output conveyor belt are passed through the upper carriage and the laying carriage. The above-mentioned documents are only a selection among a great variety of documents which show cross lappers of identical belt course.
As already mentioned, the known constructions have a relatively complex course of their card web transport belts, particularly on the upper carriage where one of said belts supporting the card web loops by more than 90° around a deflection roller delimiting the entrance zone at its lower end. The arrangement becomes additionally complex in that the second card web transport belt is also passed through the upper carriage, in the structure according to EP 0 865 521 B1 even in a manner that it accompanies the first card web transport belt at a small distance within the area of the downwardly inclined entrance zone.
Thus, it is an object of the invention to provide a cross lapper that has a more simple but still reliable guidance of the belts participating in the card web transport and card web deposition.